Bacterioferritins, Bfrs

Table 6.1 Amino-acid sequence alignment of four mammalian ferritins (Horse L chain, HoL Human L chain, HuL Human H chain, HuH Rat H, RaH) and of one of the ferritins, FTN, and the bacterioferritin, BFR of...

Another member of the ferritin family found in bacteria is bacterioferritin (BFR). BFR has the same 24-meric... 

Figure 32. Active site structure of bacterioferritin (Bfr) from Azotobacter vinelandii (A) oxidized Bfr (PDB code 2FL0), and (B) reduced Bfr (PDB code 2FKZ).

Figure 14-3 Effect of pre-treatment of E. coli bacterioferritin on aerobic oxidation of Fe2+ reflected by an increase in absorbance at 340nm associated with the oxidation of Fe to Fe +. (a Addition of 200 pM Fe " to 0.1 m Hepes buffer (pH 7.1) (B) addition of 200 pM Fe + to O.S pM apo-Bfr (C) addition of 200 pM Fe + to 0.5 pM apo-Bfr pre-treated with 12.5 pM Cu (15-minute incubation prior to addition of Fe ) (D) addition of 200pM Fe to 0.1m Hepes buffer (pH 7 i) containing 12.5 pM Cu. ...

Addition of Fe " to the E128R/E135R Bfr dimer resulted in the rapid oxidation of the Fe + (Figure 14-6). Unlike the wild-type 24-meric bacterioferritin, addition of 30 Fe + per dimer generated a brown precipitate assumed to be insoluble ferric hydroxide species. However, at a ratio of 15-18 Fe +/dimer a clear brown solution was formed consistent with the Fe + ions remaining associated with the soluble protein. 

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